and then the count matches.
Further update: My "original" and "change to" lines are not swapped. I'm using "original" and "change to" in reference to the code in my post above. I have added some text above to clarify which line is the "original" line and which lines are the "changed" lines.

There is a $2 bill. Just try finding one nowadays. Apparently the U.S. MintBureau of Engraving and Printing (thanks for the correction halley) is still printing them, but it must not be issuing large quantities because I almost never see one. I think it's unrealistic to expect to be able to make $100 with 50 $2 bills, for example.

There is a $2 bill. Just try finding one nowadays. Apparently the U.S. Mint is still printing them, but it must not be issuing large quantities because I almost never see one. I think it's unrealistic to expect to be able to make $100 with 50 $2 bills, for example.

Just a total nit, but the US Bureau of Engraving and Printing makes the paper stuff in D.C.; the US Mint makes the coins in Denver and Philadelphia.

If you visit the USBEP, or their website, you can order as many $2 bills as you like, even in odd collectables such as uncut sheets of multiple consecutively-numbered bills.

Yes, except all the $2 uncut sheets are listed as "Temporarily out of stock." $2 "Single Star notes" (series 2003) are sold out. The $2 "Independence notes" (series 1995) appear to be available at $6.95 each. Making $100 with 50 of those will cost you $347.50. Plus tax, I expect.

The two dollar bill is available from banks, like the $1 gold-colored coins. You find $2 bills at racetracks, mostly. People tend to avoid them, because they're so easy to mistake for $1 bills.

Since the original problem omitted $2 bills, there doesn't seem any compelling reason to include them. But I submit that it's no less reasonable to make change with 50 $2 bills, as it is to do it with 100 $1 bills.